Chapter 22 page 5981. What is the commonly accepted age of Earth? a) 4. 6 Billion years 2. Which of the following was not a source of heat for the early Earth? a) hydrothermal energy 3. What are small asteroids called? a) meteoroids 4.
What is the process by which a planet becomes internally zoned when heavy materials toward its center and lighter materials accumulate near its surface? a) Diffentiation 5. Where is most of the North American Precambrian shield exposed at the surface? a) Canada 6. What mineral can be used to radio metrically date Earth’s age? a) zircon 7. Refer to Figure 22-6.
What name is given to the core of the modern-day North American continent that formed in the Proterozoic? a) Laurentia 8. What is the name of the first super continent which formed near the end of the Proterozoic? a) Laurentia 9) What volcanic process most likely formed Earth’s atmosphere? a) differentiation 10) Why is ozone a necessary component of Earth’s atmosphere? a) It fillers out most of the sun’s UV radiation 11) Why is Earth’s atmosphere rich in nitrogen (N) and carbon dioxide (CO 2) today? a) because they can not escape Earth’s gravity 12) Rearrange the following phrases to create a cycle map that describes the formation of Earth’s early crust. a) 1. upper mantle cooled and crystallized 2. sediments formed 3. sediments drawn down into subduction zones 4.
Partial melting of sediments and subducted slab 5. Magma with new chemical composition formed 6. Granite crust formed as magma crystallized 7. Subduction continued forming more magma 8. crust weathered 13) Explain how geologists have determined the age of Earth? a) Radio metric dating has determined that the z iron grans in the sedimentary rocks are between 4.
The Essay on Million Years Earth Formed Volcanoes
The Earth formed when the sun and its forming of planets formed when a cloud of dust and gas condensed 4. 6 billion years ago. In large areas, iron sinks to the center forming the core. The Mantle is made up from primarily of the minerals olivine and pyroxene. It takes up 80% of the planet. The oceanic crust typically differ from continental crust because Earth's surfaces cooled below 100 degrees ...
1 and 4. 2 billion years old. 14) Discuss the relationships among the formation of the continents, the atmosphere and the oceans. a) The relationship between the formation of the continents, the atmosphere and the oceans is the most abundant gases of the Earth’s crust.
They play two huge roles in all 3 of these formations. 15) What geologic evidence suggests that free oxygen was accumulating in Earth’s atmosphere during the Proterozoic? a) These formations are mined 20 a source of iron and can be mined for a profit. 16) What geologic evidence suggests that free oxygen was accumulating in Earth’s atmosphere during the Proterozoic? A) The existence of red beds 17) What is the difference between prokaryotes and eukaryotes? Which appeared first in the fossil record? a) Prokaryotes is an organism that is composed of a single cell and a eukaryote is an organism that is composed of cells that contain a nucleus, prokaryotes. 18) What characteristics of continental crust allow it to “float” higher on the mantle than oceanic crust? a) less dense material had the tendency to float on more dense material 19) Why are oro gens deformed? a) The immune energy of colliding continents deformed these origins.
20) What is the significance of the Edicara fauna? a) The Edicara fauna were thought to be the ancestors of complex proterozoic animals 21) Discuss the evidence that suggests that most members of the Edicara fauna were immobile? a) There is no evidence of tracks on trails.
